Issues with canning on ceramic or glass stovetops

Janet Hackert, Nutrition and Health Education Specialist,
Harrison County, University of Missouri Extension

A common question about canning foods is this: “Is it OK to can on
my ceramic or glass stovetop?”

First, check the recommendations of the particular stove’s manufacturer.
Some say absolutely not, while others say it is OK, but with certain
stipulations.

The general recommendation for canning is that the canner not be
more than 2 inches wider than the burner or heating element. With a
ceramic or glass stovetop, this is an even greater concern because of
damage that can occur. When the canner sits on the hot burner, it reflects
heat back down on the stovetop. When the canner is wider, it reflects
and traps more heat. These non-burner surfaces are not designed to handle
that much heat and can be damaged by discoloration, burner damage, cracking
the stovetop or fusing the metal pot to the glass stovetop.

Another concern with this type of stovetop is that if a canner is
dragged across the top, it can scratch the cooking surface. This must
be avoided, even when the canner is full and heavy.

Many glass stovetops have auto-shutoffs, which can prevent sufficient
heating. The stove is designed to shut off when heat is excessive. However,
if the heat shuts off during the canning process, the required continuous
processing time cannot be reached, resulting in food that is not safely
canned.

A stove with a smooth top requires a flat bottom canner to work properly.
For boiling water canning, a large, flat, smooth-bottomed stock kettle
can be used by inserting a rack inside the kettle to keep jars off the
bottom of the pot. Canning rings can also be used to elevate the jars.
The pot must be big enough to fill the water to 1 to 2 inches above
the tops of the jars and to allow boiling water to circulate around
the jars. Some pressure canner makers are making flat, smooth-bottomed
pressure canners, but it is recommended to check with the stove manufacturer
to make sure they will work properly and safely together.